Process of pasteurizing milk



NITED STATES ATENT OFFICE.

LORENZO G. FAGERSTEN AND CLAUS F. P. KORSSELL, OF CHICAGO, ILLINOIS.

PROCESS OF PASTEURIZING MILK.

SPECIFICATION forming part of Letters Patent No. 566,268, dated August18, 1896. Application filed June 27, 1895. Serial No. 554,246. (Nospecimens.)

To aZZ whom it may concern.-

Be it known that We, LORENZO G. FAGER- STEN and OLAUs F. P. KORSSELL,citizens of the United States, and residents of Chicago, in the countyof Cook and State of Illinois, have invented certain new and usefulImprovements in Processes of sterilizing or Pasteurizing Milk, ModifiedMilk, and Cream, of which the following is a specification.

The objects of our invention are to preserve or pasteurize milk,modified milk, and cream Without physical or chemical change from thecondition in which they are found by destroying germs, ferments, orother elements of decomposition by an inexpensive and simple processWithout the addition of sugar or other preservatives, and, further, toapply means whereby the finished article can be shipped and handledwithout the risk of the agitation of the package churning the butter outof the substance.

In carrying out our process We place the article to be treated inpackages of any size desired at ordinary temperatures, also placing inthe top of the package a hydrocarbon of high melting-point, say about125 Fahrenheit, or any similar substance, as paraffin, wax, 850.,sufficient to form a covering-layer, When melted, on the surface of thearticle under treatment. Space is also left in the top of the packagefor a volume of atmospheric air, with which the package is then charged,of sufficient pressure or of adequate relative proportion to thequantity of the liquid and the size of the package to insure a pressureduring the process commensurate with the increasing vapor-tension, thegaspressure to exceed the vapor-tension by one atmosphere or more at anystage during the process. After thus charging the package it is thenhermetically sealed and subjected to heat so regulated that it does notat any time exceed the conductivity of the substance under treatment.The heating part of the process is completed when the temperature of thesubstance under treatment has reached about 230 Fahrenheit.

All mechanical agitation or churning, of the contents, which would favorthe separating out of the butter or fats, must be carefully avoideduntil after the contents have been rapidly cooled to thesolidification-point of the hydrocarbon, paraffin, wax, or other similarcovering on the top of the substance, when it Will be found that thecontents are inhibited from agitation or churning under ordinaryhandling.

We do not claim, broadly, the use of paraffin, wax, or similarsubstances in the preserving of foods, but only the use of them toprevent churning of milk during transportation and handling.

WVe claim 1. The process of sterilizing or pasteurizing milk, modifiedmilk, or cream'by heating it in hermeticallysealed original packages,the package being charged With a superimposed volume of commonatmospheric air sufficient to develop a pressure exceeding by oneatmosphere or more the vapor-tension generated at any stage of theprocess, and at any temperature used, thus preventing any vaporizing ofthe article under treatment.

2. The process of sterilizing or pasteurizing milk, modified milk, orcream, by placing the article to be treated in original packagestogether with a hydrocarbon of high meltingpoint, paraffin, wax, orsimilar substance, then charging the package With common atmosphericair, sufficient to develop a pressure exceeding by one atmosphere ormore, the vapor-tension generated during the following steps, and thenhermetically sealing the package and subjecting it to heat so regulatedas not to exceed the conductivity of the article under treatment at anypoint of the package or during any stage of the process; the degree ofheating depending upon how long it be desired to keep the article andranging from 140 to 230 Fahrenheit.

LORENZO G. FAGERSTEN. CLAUS F. P. KORSSELL.

WVitnesses:

FRED P. KENNEDY, HENRY WEIGAND, Jr.

